Thanks for the articles. I have actually ready those a little while ago. In recent days I have been doing more research on grounding probes and current in the tank, and one thread here I recently read:
http://www.canreef.com/vbulletin/sho...g+probe&page=3 suggests that they are a good idea and lots of people have been using them without issue.
I do have a GFCI on this tank (the shallow Lagoon), and it does not trip. But when I put my hand in that tank last week (I had a cut on my finger) I got a nice zap! Ouch! I know it is not just the salt in the water stinging me because I can put that same cut hand into my 150g mixed reef without getting zapped and neither tanks have grounding probes.
I started to do some debugging (unplugging stuff) until I found what was leaking voltage. Well, it wasn't pretty.. My return pump and all 3 tunze powerheads are leaking a little bit of voltage. Individually they don't seem to be leaking a lot, but when you put all 4 components together it is enough to give me a zap on my cut finger but not trip the GFCI. I stuck my non cut up finger in that tank and no zap so I don't think it is cause of enormous concern, but something I should probably address with a grounding probe. At this point I'm not sure I want to trash all 4 components, they are brand new
